Overloaded machinery spawning the floor's ghouls, finally crashed by the train blast in the abyss.
The death of the Station Mimic caused even more ghoul generators to explode, with reports of additional blown generators at several station 72s. Carl had hoped Prince Maestro's fall into The Abyss would compound the damage, but suspected Maestro bailed on his sponsorship after being teleported away, producing less destruction in the pit than intended.
With the whole ghoul system already overloaded, Carl reasoned that one more big shock anywhere on the floor might bring it down entirely — which is exactly what The Nightmare Express's detonation accomplished. Daniel Bautista reported feeling the generator explode from across the floor, and his group began moving in toward the stairwells. Ghouls still trickled out at Station 36 afterward, alongside full-sized Krakaren monsters.
Machinery seeded through the rail network's stations; known chiefly by the shockwaves of its detonations.
The infrastructure sustaining the floor's ghoul plague, and the target of Carl's whole scheme.